Aarrow Acorn 4 Specification sheet

Aarrow Fires Ltd
The Fireworks
Bridport
Dorset, DT6 3BE
Great Britain
Tel. [phone]
Fax. [phone]
www.aarrowfires.com
Acorn
Multifuel Stoves
Operating & Installation Manual
PLEASE RETAIN THESE INSTRUCTIONS FOR FUTURE REFERENCE
The Acorn 4 Multifuel Stove (shown above)
Rev 2
Part No: AFS1126
March 2004

Congratulations on your choice of an Aarrow Stove.
More than 20 years experience has been put into the development of
our Acorn Multifuel to ensure ultimate performance and years of
trouble free enjoyment.
Every detail on the fire has been carefully engineered and designed
which is why we are so confident in the reliability of our product
that we offer a 3 year guarantee.
Should you have any questions about our Acorn Stoves that are not
covered in this manual, please contact the Aarrow dealer in your
area, or call our Technical support department on
01308 427234
© COPYRIGHT 2004
Aarrow Fires Ltd
This booklet has copyright & may not be
copied in whole or part or be used for any
purpose other than that for which it is
supplied without express written consent
from Aarrow Fires Ltd.

INTRODUCTION Page
Safety Notices 5
The Principle of the Fire 5
Check List 6
Technical Data 7
INSTALLATION Page
General Precautions 8
Handling 8
Hearth 8
Combustible Materials 8
Air For Combustion 8
Firebox Liner Panels 9
Removal of the Throat Plate 9
Fitting the Optional Floor Fixing Kit 9
Assembling the Multifuel Grate 10
Flues & Chimneys 11-14
Add in Boilers 15-16
OPERATING INSTRUCTIONS Page
AirInlet Controls 16-17
Airwash System 16-17
Multi-Purpose Operating Tool 17
Fire Door Glass 17-18
Adjusting the Door Hinges 18
Fuel Types 18-19
Lighting the Fire 19
Extended Burning 19-20
De-Ashing 20
Over-Firing 20
Cleaning & Annual Maintenance 21
Final Check List 22
Parts List 23-25
GUARANTEE
Guarantee 26
Customer Registration 26
SERVICE RECORD
Service Record 27
Final Factory Check List 28
3
CONTENTS

WARNING
TO ALL MULTIFUEL USERS
PETROLEUM COKE
SOME OF WHOSE BRAND NAMES ARE
"CALCO", "PETROCOKE" OR "WONDERCO"
MUST NOT BE BURNED IN THIS APPLIANCE
TO USE THESE FUELS WILL INVALIDATE THE
APPLIANCE GUARANTEE
IF IN DOUBT CONTACT THE SOLID FUEL ASSOCIATION
TELEPHONE NUMBER 0800 600 000
www.solidfuel.co.uk
THE USE OF SPARE PARTS OTHER THAN THOSE SUPPLIED
BY AARROW FIRES LTD WILL INVALIDATE THE
APPLIANCE GUARANTEE.
4Acorn Multifuel Stoves

Acorn Multifuel Stoves 5
INTRODUCTION
SAFETY
A fireguard conforming to BS 8423: 2002 should
be used in the presence of children and old/or
infirm people. If the appliance is used with the fire
door open, a spark guard conforming to BS 3248
should be fitted.
Do not use aerosol sprays or any other flame
near the appliance under fire.
Do not fit an extractor fan in the same room as
the appliance.
Fire cement is caustic, hand and eye protection
should always be worn, prolonged contact with
the skin should be avoided.
Aarrow Fires Ltd will not be responsible for any
consequential or incidental loss or injury
however caused.
Before continuing any further with the installation
of this appliance please read the following guide to
manual handling.
• Always obtain assistance when lifting the
appliance.
• When lifting always keep your back
straight. Bend your legs not your back.
• Avoid twisting at the waist. It is better to
reposition your feet.
• Avoid upper body/top heavy bending. Do not lean
forwards or sideways when handling the fire.
• Always grip with the palms of your hands.
Do not use fingertips for support.
• Always keep the stove as close to the body as
possible. This will minimise the cantilever
action.
• Use gloves to provide additional grip.
THE PRINCIPLE OF THE FIRE
Your Aarrow Fire is built to the highest standard of
craftsmanship using the best materials and the most
modern equipment available. It is a highly efficient
and sophisticated piece of machinery and when
properly installed and operated it should provide a
lifetime of heating satisfaction.
Safety is the most important consideration when
installing your fire. If not properly installed and
operated a house fire may result. installation must
comply with the Building Regulations and conform
to all relevant fire safety standards.
Aarrow Fires produce a variety of appliances
ranging from units, which are traditional in style to
stoves which are modern in appearance, all
bristling with "High Tech" features.
Model types include simple room heaters,
convectors, integral boiler models and inset units.
Your Aarrow Fire is constructed from either single
or twin wall steel strengthened where necessary.
Cast iron is used where appropriate for decorative
features.
All fire doors are fitted with special high
temperature ceramic glass panels through which
the fire can be viewed.
Multifuel stoves are fitted with a cast iron grate to
give full multifuel facility and positive de-ashing.
All models except integral boiler models are lined
with firebricks or heat reflective panels which
ensure complete combustion and provide a good
heat store to even out fluctuations in burning.
An internal throat plate produces turbulence to
encourage secondary combustion and directs the
flue gas around the whole upper firebox before
allowing it to escape up the chimney.
On multifuel appliances the primary air for burning
enters the ash pit chamber beneath the grate,
controlled by the air inlet mechanism.
Aarrow Fires are also fitted with an "air wash" so
called because it provides a curtain of high speed
preheated air behind the glass to help keep it clean
and to provide secondary air/over draught.
The provision of two inlets on all multifuel stoves
gives a wide range of primary air/secondary air,
under draught/over draught combinations.
The optimum settings will only be established by
experience in firing the appliance, and will depend
on type of fuel, the position of the appliance in the
house, condition of chimney etc.

Inside the appliance you should find the following:
6Acorn Multifuel Stoves
CHECK LIST
Part Description & Visual Aid
(not to scale)
Acorn 4 Multifuel
Quanity Part No.
1. Grate bars
5
2. Integral
front brace/
reatainer
1
3. Throat
plate 1
4. Flue
spigot 1(4”)
5. Hot plate
1(4”)
6. Ash pan
1
7.Operating
tool 1
8. Rear
liners 1
9. Side liners
2
10. Fire door
handle 1
11. Instructions 1
The model and Serial Number of your fire can be found stamped into the casing,
centrally just below the bottom edge of the fire door aperture.
Acorn 5 Multifuel
Quantity Part No.
5
1
1
1(4”)
1(4”)
1
1
1
2
1
1
AFS001
AFS1101
AFS1086
AFS064
AFS1094
AFS008
AFS1141
AFS009A
AFS1092
AFS205
AFS1126
AFS001
AFS1101
AFS1018
AFS064
AFS1059
AFS008
AFS1141
AFS009A
AFS1058
AFS205
AFS1126

Acorn Multifuel Stoves 7
TECHNICAL DATA
Room Min/Max
Room Heater Only Output (kW) 1- 4.5
TECHNICAL DATA Acorn 4
Multifuel
Room Heater with Domestic Hot
Water with add in boiler type Type 7
Max Output to Room (kW)
Max Output to Water (kW)
3
1.5
Height (mm) 458
Width (mm) 355
Depth (mm) 350
Height to Centre of Rear Flue 360
Depth from Back to Centre of Flue 90
Flue Diameter (mm) 102 (4”)
Weight Unpacked
Packed
43 Kg
46 Kg
Acorn 5
Multifuel
1 - 5
Type 0
3
2
483
395
350
387.5
96
102 (4”)
44 Kg
47 Kg

8Acorn Multifuel Stoves
INSTALLATION
GENERAL PRECAUTIONS
Note - All installations must conform to the
appropriate building regulations.
The Building Regulations for England and Wales
2000 ref Approved Document J 2002 edition
(issued by the DTLR).
The Building Standards (Scotland) (Consolidation)
Regulations.
Detailed recommendations for installation of
appliances, chimneys and flues are outlined in the
current issue of the following British Standards:-
BS6461, BS8303 and BS4543.
Any Manufacturer's Instructions must not be
taken as overriding statutory requirements.
During installation ensure that adequate
precautions are taken to avoid unnecessary risk to
yourself or any householder. In particular the
danger from the caustic nature of the fire cement
should be avoided by using these accepted
methods:
•Wear gloves when handling fire cement.
•Wear goggles when chiselling or looking up
chimneys.
Make sure that Building Regulations are adhered to
during installation along with any local by-laws.
In the case of heating systems make sure that the
pipe work is correctly bonded to ensure electrical
earthing.
HANDLING
By the time you read this you will appreciate the
weight of the appliance. The Safety and handling
guidelines as set out on page 5 of this manual
should be followed.
To make movement easier internal fittings, grates,
firebox liners, flue outlets, hot plate, throat plate,
etc., can be removed.
Care should be taken to make sure that the hinges
are not damaged during installation.
HEARTH
The fire should be installed to stand on a
constructional hearth of non-combustible materials
not less than 125mm (5'') thick conforming to
Building Regulations. Dimensions of the hearth
should project at least 300mm (12'') forward of the
front of the appliance and 150mm (6'') at the sides.
The surface of the hearth should be free of
combustible materials. In most buildings with solid
concrete floors the requirement will be met by the
floor itself, but mark the perimeter of the hearth to
ensure floor coverings are kept well away or use
different levels to mark the hearth perimeter.
COMBUSTIBLE MATERIALS
A gap of at least 450mm (18'') should be allowed
between the appliance and any combustible
materials including furnishings. Adjacent walls
should be of suitable non-combustible
construction, preferably brickwork. In large
fireplaces take care that any supporting beam is
protected by a 13mm (0.5'') sheet of
Masterboard/Supalux spaced 13mm (0.5'') off the
surface with strips of non-combustible material
- not wood.
Make sure that there is a gap between an
uninsulated flue system and any combustible
material. This gap must be at least 3 x the outside
diameter of the flue pipe, or 1.5 x the flue diameter
to non combustible surfaces. See the illustration on
page 14.
AIR FOR COMBUSTION
There must always be a permanent means of
providing air for combustion into the room in
which the fire is installed. A permanent vent with a
total free area of at least 550mm2for every kW
rated output above 5kw should be connected
directly to the outside air or to an adjacent room
which itself has a permanent vent of the same size
direct to the outside air. The fitting of an extractor
fan to either of these rooms is not recommended.

FIREBOX LINER PANELS
The Acorn Multifuel stoves have reflective liners to
the sides and back. The throat plate sits on top of
the side and rear panels. These should come fitted
to your fire, if however they are not proceed as
follows to fit them.
•Remove the front brace retainer.
•Set the small liner into the back of the fire.
•Insert side liner panels
•Fit the throat plate with the single bend and two
cut outs to the front facing up. The projecting lugs
sit on top of the side liners. The long centre tab on
the back edge rests on the rear liners. The shorter
turn-down tabs against the vertical face.
•Replace the front brace retainer.
Note: Neither the rear firebox liners nor the side
firebox liners are "handed", both faces are
suitable for direct contact with the fire.
Fig. 1 Liners inserted in Acorn
Fig. 2 Inserting throat plate
Fig. 3 Liners, throat plate and
grate in the Acorn.
REMOVAL OF THE THROAT PLATE
Blocked chimneys cause dangerous fumes to
escape. Remove the throat plate at least monthly to
clean. Keep chimney and flue ways clear.
FITTING THE OPTIONAL FLOOR
FIXING KIT
Once the stove is in the correct position it is
recommended that the fire is fixed to the floor for
safety purposes:
You will need a No. 2 pozi drive screw driver to
carry out this operation. Place the brackets each
side of the appliance.
Fig. 4 Lining up the bracket
Slide the small threaded hole underneath the gap
(as shown above) and turn inside so the both holes
match the pre-drilled one. Repeat for the other side.
Fig. 5 Inserting and tightening the screws.
When both are in place, tighten the screws until
they are firmly inserted.
Then proceed to drill your hearth and insert and
anchor bolt or similar fixing (Not supplied in kit)
and bolt down the brackets once the appliance is in
place. For further instructions please consult the
floor fixing instructions attached to the kit.
Acorn Multifuel Stoves 9
INSTALLATION

MULTIFUEL GRATE
GRATE
The grates in the Acorn Multifuel units comprise a
series of reciprocating cast iron bars seated on a
pivoted "comb". All bars in the grate are identical,
but every other bar is turned through 180 degrees,
with the ends of the bars marked "H" sitting on the
high sections of the comb, and the ends marked "L"
sitting on the low sections.
ASSEMBLING THE GRATE
To assemble the grate, fit bars to low sections of the
comb first, inserting end marked "H" into rear
channel with groove on underside of bar located on
upstand tab, and then lowering end marked "L"
onto the low section of the comb. The upper bar is
fitted in a similar manner, but with the end marked
"L" inserted in the rear channel, and the end
marked "H" seated on the high section of the comb.
10 Acorn Multifuel Stoves
INSTALLATION
GRATE BAR REPLACEMENT
After extended use it may be necessary to
replace some of the grate bars.
Periodic inspection of the bars is recommended
and the removal of any nails or wire that may be
present after burning wood. All the grate bars in
each appliance are identical and can easily be
lifted out after removal of the fuel retainers.
Remove damaged grate bars and replace with
casting of the same type, fitting as per
instructions above. (Check Identification letters
on the casting when reordering).

FITTING THE FLUE OUTLET AND
HOT PLATE
The flue outlet spigot is found inside the appliance.
It is removed by turning clockwise.
Smear a very thin layer of fire cement on the faces
of the flue outlet and the blanking plate. Fit the
outlet to the appliance in the desired position.
Lock into place by rotating anti-clockwise and
tighten by tapping with a block of wood and mallet
from the inside of the appliance. Similarly, fit the
blanking plate to the unused opening. Clean off any
surplus fire cement.
Place appliance on the hearth and make sure that it
is level and does not rock. Connect the chimney
ensuring all joints are sealed with fire cement.
Fig. 6 Flue and Spigot Fitting
FLUES AND CHIMNEYS
Please remember that chimney draught is
dependent on four main factors:
•Flue gas temperature.
•Flue height.
•Flue size.
•Flue terminal.
The stove must be connected to a suitable and
efficient flue that provides a good up draught to
safely take the products of combustion (fumes)
from the stove outlet to the outside air. To ensure a
good updraught it is important that the flue gases
are kept warm and that the flue size suits the stove.
The termination of the outlet at the top of the flue
also needs to comply with the Building
Regulations. The minimum effective height of the
flue must be at least 4.5 metres from the top of the
stove to the top of the flue outlet. When warm the
flue draught should be between 0.1 and 0.2 mb.
A chimney may comply with the regulations but
still be subject to down draught and similar
problems. A chimney terminating above the ridge
level is generally less likely to suffer such
problems.
If a new chimney is being provided it should fully
comply with the relevant Building Regulations that
specify the requirements for solid fuel burning
installations. Suitable types of chimney include the
following.
Masonry chimney built with clay or concrete
liners, or a chimney block system meeting Building
Regulations. These types of chimney should be
installed in accordance with the Building
Regulations and BS 6461: Part 1.See page 12 for a
typical installation diagram.
Factory made insulated chimney complying
with BS 4543: Part 2 (often called "Class 1
prefabricated metal chimney"). These types of
chimney should be installed in accordance with the
Building Regulations and BS 7566: Parts 1 to 4.
See page 12 for a typical installation diagram.
Acorn Multifuel Stoves 11
INSTALLATION

Due to the gradual introduction of European
Chimney Standards chimneys will be specified
according to their performance designation as
defined in BS EN 1443 that covers the General
Requirements for chimneys. The minimum
performance designation required for use with solid
fuel burning stoves is T450 N2 S D3.
The flue and chimney installation must be carefully
checked by a competent person before fitting the
stove to ensure it is suitable and will work safely.
If the chimney is old (ie built of brick or stone
without a liner) or being opened up for reuse
additional checks and smoke testing as described in
Appendix E of the Approved Document J 2002
Edition should also be carried out to ensure the flue
and chimney are in good operating condition.
Unless the existing flue is in good condition with
suitable access for collection and removal of debris.
If the flue size is more than 225mm (9 inches)
diameter or 200 x 200mm square, a suitable lining of
150mm (6 inches) diameter should be fitted, or if the
flue length is over 5.5 metres one size larger than the
appliance outlet should be fitted. This should be a
double skin stainless steel flexible flue liner that is
independently certified for use with solid fuel.
Details of suitable linings for use with solid fuel are
given in the Official HETAS guide that can be
viewed on their website at www.hetas.co.uk
It is also important that suitable flue pipe
complying with the Building Regulations is used to
connect the stove to the flue in the chimney and that
suitable access is provided into the flue for regular
inspection and sweeping of the flueways.
The installer should comply with the Building
Regulation requirements in respect of providing a
Notice Plate giving details on the chimney, flue
lining, hearth and fireplace installation. Approved
Document J of the Building Regulations for
England and Wales is available from The
Stationery Bookshops and can also be viewed at
the ODPM website at:
www.safety.odpm.gov.uk/bregs/brads.htm
Details on the relevant Building Regulations and
BS British Standards are given in the "General
Precautions" section page 8 of these instructions.
Chimneys should be as straight as possible.
Horizontal runs should be avoided except where
the rear outlet of the appliance is used, in which
case the horizontal section should not exceed
150mm (6'') in length.
If the fire appears to be working hard but produces
very little output to the room it is likely that
excessive draw is present in the chimney, and that
heat is being sucked out of the appliance and up the
chimney. If this is the case we recommend the
fitting of a draught stabiliser in preference to a flue
damper, in the interest of safety and efficiency.
We do not recommend the use of a damper when
burning solid fuel.
FOR ALL APPLIANCES
Access for cleaning the flue should be incorporated
in the system other than through the appliance (e.g.
a soot door or access through register plate).
Purpose-made soot doors and inspection lengths
are available from manufacturers of all systems.
Ensure that the whole length of the flue can be
reached from the soot door.
Note: if the appliance is fitted with a draught
stabiliser or if one is fitted to the flue pipe or
chimney in the same room as the appliance, then
the permanent air entry opening (or openings)
should be increased by 300mm2for each kW of
rated output.
For advice on flues and chimneys contact;
NACE (National Association of Chimney
Engineer): telephone [phone]
www.nace.org.uk
or
NACS (National Association of Chimney
Sweeps): telephone [phone]
www.chimneyworks.co.uk
12 Acorn Multifuel Stoves
INSTALLATION

Acorn Multifuel Stoves 13
INSTALLATION
TYPICAL REAR FLUE OUTLET

14 Acorn Multifuel Stoves
INSTALLATION
TYPICAL METAL INSULATED CHIMNEY SYSTEM
TO BE INSTALLED TO THE CHIMNEY MANUFACTURERS INSTRUCTIONS IN COMPLIANCE
WITH BUILDING REGULATIONS AND BS7566 PTS 1-4
PLAN VIEW OF REGISTER PLATE AND
CLEARANCES FOR NON INSULATED FLUES
A is minimum clearance for non-insulated flue =
1.5 x D to a non-combustible surface/material
or
3 x D to combustible surface/material

ADD IN BOILERS
Acorn 4 & 5 multifuel stoves offer the option of a
slab boiler, which occupies the position of the rear
firebox liner panels.
Fitting:
•Remove the fuel retainers, rear firebox liner
panels and throat plate.
•Knock out the blanking discs in the back
plate corresponding to the terminals on the
boiler.
•Introduce the boiler to the appliance
through the main fire door and locate the
terminal pipes through the back plate holes
and seal around boiler terminals with fire
cement.
•Engage locking nuts to the thread of the
terminals and tighten to secure the boiler in
position, ready for connection to flow and
return pipes.
•Replace throat plate (slab boilers only) and fuel
retainers.
Do not fit a throat plate with a cantilever boiler.
Note: On boilers the terminal which is
approximately flush with the edge of the boiler
must be fitted uppermost, to prevent "Kettling".
WATER CONNECTIONS
Heating systems
The size of the heating system which can be run,
will depend on the output rating of the appliance.
It will be necessary to work out heat loss
calculations for the system proposed in order to
establish the kW/hr rating. An appliance that will
meet this figure can then be chosen; (for boiler
outputs please refer to the brochure).
The constructional requirements of installing and
connecting the appliance also need to be taken into
account when selecting. Design and calculations
for individual heating systems should be carried out
by a qualified heating engineer. In many cases your
supplier will be able to offer advice and assistance.
Direct Systems
Stainless steel boilers, either factory fitted or
retro-fitted as add-in boilers enable connection to
direct systems to be made without the need to
change the cylinder or to fit an expansion tank. This
applies to domestic water supply only and should
not be done when in an area with soft water.If
radiators are used then an indirect system must be
utilised.
To connect the cylinder use 28mm copper pipes.
Ensure that the pipes rise continuously to the
cylinder.
Ensure that the runs are not too long, i.e. 20ft
maximum each for flow and return. Install the
cylinder above the level of the fire, and as close to
it as possible. (the higher the cylinder the faster the
circulation). Ensure that no valves are present in the
circulating pipes.
Indirect Systems- The Domestic Hot Water
Circuit
In addition to providing hot water the primary
circuit is essential in providing a "heat leak" to
absorb excessive heat produced in the event of the
circulation pump shutting down.
Heat is produced in varying quantities while the
fire is alight and care must be taken to ensure that
effective circulation can occur around the primary
circuit to carry heat away and thus stop boiling. The
output of any radiator installed as a "heat leak"
should not be less than 10% of the rated output of
the appliance. The radiator should not be fitted
with a control valve.
The cylinder must be of the indirect type with a
minimum capacity of 110 litres, conforming to
BS 1566 part 1.
Primary flow and return pipes should be 28mm
diameter. The cylinder should be installed at a
higher level than the appliance, and as close to it as
possible (the higher the cylinder the faster the
circulation). The flow and return pipes should not
be longer than 20ft each. Pipe runs should rise
continually from the boiler to the cylinder.
A radiator of approximately 25 sq.ft. should be
connected into the primary circuit, if installed in the
bathroom it provides a means of drying towels in
the summer.
Safety Vent Circuit
This circuit consists of a cold feed pipe, expansion
pipe, and expansion tank. The possibility that water
may boil can never be completely ruled out, and it
is therefore vital to ensure that cold water can be
supplied to the boiler and steam vented from it at all
times.
Acorn Multifuel Stoves 15
INSTALLATION INSTRUCTIONS

16 Acorn Multifuel Stoves
INSTALLATION INSTRUCTIONS
The expansion tank should have a capacity of at
least 7 % of the system's water capacity. The cold
water feed pipe should be at least 22mm diameter.
There must not be any shut off valves in the circuit.
Pipes should be run to avoid air locks. A spring
safety valve should be fitted to the expansion pipe
close to the boiler.
It is often possible, and is good practice, to utilise
the primary flow and return as part of the safety
circuit. The ball valve should have a copper ball.
The overflow pipe from the expansion tank should
be 28mm diameter copper. Pipes in unheated
spaces must be lagged.
FINAL CHECK
Before handing over the installation to the
customer it is strongly recommended that the
appliance is lit and the functioning of the chimney,
hot water and heating system is checked.
A checklist (Pre-lighting Checks) appears in the
Operating Instructions, but in addition to this the
installer should:
•Operate the heating system and set the
pump head.
•Balance the radiators.
•Re-vent and ensure no air locks.
•Check the circulation round the primary
system and the heat leak radiator,
particularly when the pump is running, to
ensure circulation is not reversed.
•Be sure that the chimney is operating and
that ALL smoke and fumes are vented to
the atmosphere through the chimney
terminal.
•Check all joints and seals.
•Clean the outside of the appliance to
prevent any stains becoming burnt on.
•Check the flue draught which should read
1 - 2mm, or 0.1 - 0.2mbar.
The following details must be checked and
completed in full by the installer at the time of
installation. Please answer all questions as fully as
possible. Aarrow Fires Ltd can not be held
responsible for chimney or installation.
AIR INLET CONTROLS
The Acorn multifuel stoves have two air inlets:
•The air wash system (so called because its
pre-heated high speed air washes across the inner
face of the door glass, keeping it clear), which
provides over draught, and
•The oval cover; the primary air inlet
providing under draught to the base of the fire
chamber through control on the bottom of the
stove door.
PRIMARY AIR FOR MULTIFUEL
Air enters the appliance through the control on the
bottom of the fire door. The Aarrow Acorn has a
single control knob which slides left to right.
Sliding the knob to the right will increase the
amount of air intake to the stove. To decrease push
knob to the left.
AIRWASH SYSTEM
The air wash has an internal sliding plate with slots,
housed in a cover plate, and is located above the fire
door. Sliding the control knob to the right as far as it
will go achieves the fully open position. Sliding it to
the left will shut off the air inlet slots see page 17.
HOT WATER SYSTEMS
Is the boiler cross-flowed? YES / NO
Are the pipes correctly sized? YES / NO
What is the calculated output
required to heat the system?
Is a heat leak fitted? YES / NO
What is the return water temperature?
Is the pump thermostatically
controlled by a pipe stat? YES / NO
What is the height and distance of the
hot water tank above the stove?

Fig. 7 Fully Closed Fig. 8 Fully Open
Even when all the slots are completely shut a
"bleed" of secondary air will be maintained
ensuring that inflammable gases are burnt off.
DISASSEMBLE AIRWASH
The Aarrow air wash may be disassembled for
cleaning or adjustment. To achieve this, the
following procedure should be followed:
•The door should be GENTLY lifted off its hinges
so that the below operations can be carried out on a
workbench or similar level surface.
This should be done when the appliance is cold.
Fig. 9 Rear of the fire door
•Remove the glass by unscrewing the top and
bottom nuts.
•Carefully remove the glass and lift airwash cover
off.
•Unscrew the airwash spring knob from the sliding
plate.
•Remove assembly from the appliance.
•Clean and/or adjust.
•Refit using reverse procedure.
MULTI - PURPOSE OPERATING
TOOL
Your Aarrow stove comes with a multi-purpose
tool, which is used for, riddling, setting the
multifuel grate position and for emptying the ash
pan. (Fig. 10)
Fig. 10
RIDDLING
Use the operating tool for setting the grate in the
coal burning position or the wood burning position.
This means that effective de-ashing (see page 19)
takes place, and also allows the grate to be set in the
coal burning or wood burning position, as
indicated on the right hand side of the appliance.
FIRE DOOR GLASS
In the event of the door glass being broken it can
easily be replaced:
•The door should be GENTLY lifted off its hinges
so that the below operations can be carried out on a
workbench or similar level surface. This should be
done when the appliance is cold.
•Unscrew the four nuts, on the inside of the door.
•Remove the upper airwash cover and the two
lower glass clips.
•Carefully remove any pieces of broken glass, and
sealing gasket wearing suitable gloves.
REFIT NEW GASKET
•The fitting of new gasket is shown below (Fig.11a)
Fig. 11a fitting new door gasket
•Re-seat the new glass, ensuring the sealing gasket
is flat and in contact with the glass (Fig.11b)
Acorn Multifuel Stoves 17
OPERATING INSTRUCTIONS

Fig. 11b fitting new glass
•Replace the two lower retaining clips and nuts.
•Replace the upper airwash cover and nuts. Do not
over-tighten the nuts as damage may occur to the
glass (Fig.11c)
Fig. 11c tightening nuts
ADJUSTING THE DOOR HINGES
Once the appliance has been under fire for a period
of time the fire door may appear to have moved out
of alignment with relation to the door aperture or
catch. This is quite normal and due to the settling of
the casing.
The fire door can be re-aligned by the user as
follows:
•When the appliance is cold, open the fire door so
that it is at right angles to the front of the fire.
•Lift the fire door up off its hinges.
•Gently tap the hinge pins in a direction to
compensate for the misalignment (Fig. 12)
Fig. 12 tapping door hinges
•Refit the door and check to ensure it now
sits square to the body; if not repeat above steps.
FUEL TYPES
Wood- Any type of wood is suitable provided it is
well seasoned and has a moisture content below
20%. This usually implies that the timber has been
suitably stored to allow moisture to evaporate for at
least nine months in the case of soft woods, and at
least eighteen months in the case of hard wood. We
recommend that for general burning, wood should
be split into logs of no more than 130mm (5")
diameter. Larger logs can be used for overnight
burning.
WARNING wet wood must not be used as this will
greatly contribute to the creation of tar and creosote
which may, in extreme cases, run down the
chimney in liquid form. This will seriously damage
both the chimney and the appliance, and increase
the risk of chimney fire.
Note: If you have sticky tar inside the appliance or
chimney your wood is 'Green' or too wet.
Recommended Reading:
"Wood as Fuel" available from the Forestry
Commission.
Peat- Can be used in turf or briquette form, but
again the moisture content must be low.
Paper- paper will burn successfully. Burn dry
paper only or chimney damage will occur.
NEVER BURN PLASTICS OR WASTE IN
YOUR STOVE.
Coal for Multifuel only - Household coal
produces a large amount of ash and smoke and
chimney will require frequent cleaning. Therefore
soft house coal is not recommended.
Recommended fuels are as follows:
The Hetas Ltd, "Three tick" appliance approval
only covers the use of the following fuels in this
appliance;Phurnacite, Phurnacite Plus, Centurion,
Maxibrite,Extracite,Pureheat, Blazebrite, Taybrite,
Sunbrite (double/singles), Anthracite (large nuts),
and Welsh Dry Steam Coal (large/small nuts).
18 Acorn Multifuel Stoves
OPERATING INSTRUCTIONS

Approval does not cover the use of other fuels
either alone or mixed with a suitable fuel listed
above, nor does it cover instructions for use of
other fuels. For latest details please refer to Hetas
website www.hetas.co.uk.
Do not use Homefire (six sided) and smaller sizes
than Stovesse, e.g. Beans,Peas,Grains.
Do not use petroleum based solid products such
as Calco or Petrocoke.
To do so will INVALIDATE the appliance
guarantee.
LIGHTING THE FIRE
Prior to lighting the fire for the first time check
with the installer that:
•Installation and all building work is complete.
•The chimney is sound and has been swept and is
free from obstruction.
•Adequate provision for combustion air has
been made, i.e. a permanent vent of at least
550mm² per kW of rated output above 5 kW,
is fitted in the room in which the appliance
is installed.
•That Building Regulations and any local
by-laws have been followed during installation
(see installation instructions).
•All firebox liner panels are in place.
•Throat plate is in place.
•That the chimney draw has been checked and is
within specification. With the chimney warm the
draught should be between 1 - 2mm water gauge
(0.1 - 0.2mbar).
WARNING: An over drawing chimney can cause
over-firing resulting in damage to the appliance.
ENSURE THAT YOU HAVE READ &
UNDERSTOOD THESE INSTRUCTIONS
BEFORE LIGHTING THE FIRE.
ALWAYS WEAR SUITABLE PROTECTIVE
FIRE GLOVES WHEN REFUELLING YOUR
STOVE.
SOLID FUEL BURNING - Multifuel Stoves
•Ensure that the multifuel grate and ash pan are in
position and the fire doors are closed.
•Set the air wash to one quarter open position.
•Set the primary inlet to the fully open position
•Light in the normal manner with paper and
kindling, or use a fire lighter.
•If using a gas poker be sure to remove it
immediately the fire is alight.
•When the fire is well alight regulate the burning
rate by adjusting the setting on the primary air
inlet control.
•The air wash can be opened sufficiently to keep
the door glass clean.
BURNING WOOD
•Set air wash to the fully open position
•Proceed as for solid fuel but note the fire will burn
up and become established more quickly.
MIXED FUELS
•As per coal but allow additional secondary air.
•The primary air inlet can be closed and burning
regulated by means of the air wash above the door.
ANTHRACITE
Anthracite is more difficult to keep in for long
periods, consequently more care in setting the
controls and some familiarisation is necessary
when burning anthracite.
Use the smallest size fuel (Stovesse or Small Nuts).
Proceed as for manufactured smokeless fuel. Leave
the air inlet control open about a quarter or less.
Note: The high temperature paint acquires
durability by being "cured" during the initial
firings of the appliance will give off fumes which
are non-toxic, but which certain persons may find
have an unpleasant or irritant effect. Ensure that
the area is well ventilated during this time.
EXTENDED BURNING
The appliance will burn for an extended period
provided:
•Sufficient fuel is placed in the firebox.
•The controls are set correctly.
•Excess draught is not present in the chimney.
•Fire door is closed.
•If the fire goes out with unburnt fuel left in
the firebox increase the air opening slightly,
and vice versa.
Acorn Multifuel Stoves 19
OPERATING INSTRUCTIONS

In the morning
•Open the air control fully until embers begin
to glow brightly and place pieces of fuel on
the fire until it is well established.
WARNING: When wood is burnt slowly in a
closed appliance it produces moisture and tar,
which will create condensation and deposits in the
chimney. This effect can be minimised by burning
hard for a short period, about 20 minutes, twice a
day. It is usually convenient to do this morning and
night.
Note: To avoid chimney problems your fire should
not be burnt slowly for longer than 12 hours
without a period of fast burning.
WARNING: Properly installed, with a suitable
flue and chimney and operated and maintained
this appliance will not emit fumes into the
dwelling. Occasional fumes from the de-ashing
and re-fuelling may occur. However, persistent
fume emission is potentially dangerous and must
be investigated by a Hetas registered installer.
Stop using the appliance if you smell fumes or
see smoke escaping.
If fume emission does persist, the following
immediate actions should be taken.
•Open doors and windows to ventilate room.
•Let the fire die or extinguish and safely
dispose of fuel from the appliance.
•Check for flue or chimney blockage, and
clean if required.
Seek expert advice from your HETAS registered
installer. Do not attempt to re-light the fire until the
cause of the fume emission has been identified and
corrected
ASH REMOVAL
The appliance will require ash to be removed
periodically but an ash bed of approximately 20mm
(3/4'') should be maintained. Ash may be removed
with a small shovel whilst the fire is still lit by
raking the embers of a low fire to one side of the
fire box and carefully removing the ash, then
repeating the procedure for the other side. Care
must be taken not to risk burning of hands or
household objects from falling embers.
DE - ASHING
It is necessary to maintain an ash layer on the upper
surface of the grate bars, in order to protect them so
de-ashing should cease as soon as the first red
embers drop into the ash pan. Further de-ashing
will cause heat build-up under the grate, which will
considerably shorten its life. This operation should
be carried out with the doors closed to prevent dust
escaping into the room.
•Move up and down vigorously the riddling
lever (ash will fall into the ash pan beneath
the grate).
•When de-ashing is complete re-set grate to
previous position.
• Empty ash pan.
Note: Do not force the riddling mechanism.
TO EMPTY THE ASH PAN Open the fire
doors. Fit the fork end of the operating tool into the
ash pan and remove from the ash pit chamber.
WARNING: The ash can be very hot. Empty only
to a metal container. Even if the ash appears cold,
red-hot pieces of ash may be concealed and could
easily start a fire or cause an injury.
CLINKER
The formation of clinker suggests that the unit is
being over-fired. Any clinker forming on the grate
should be removed when cold.
OVER-FIRING
Do not over fire your appliance. Using flammable
liquids or too much wood or firing the stove at
maximum, for prolonged periods may result in
over-firing. If the chimney connector or casing glows
red the appliance is being over-fired. If this occurs
immediately close all air inlets to the appliance to
reduce the air supply to the fire. Should a chimney
fire occur immediately close the appliance down.
Get everyone out of the house and call the fire
brigade. A chimney fire may cause structural
damage to the chimney. Do not use the appliance
until the chimney and connector have been
inspected and any damaged parts have been repaired
or replaced. This should be done by a competent
person such as a HETAS registered engineer.
20 Acorn Multifuel Stoves
OPERATING INSTRUCTIONS